updated 09:02 am EDT, Mon June 16, 2014

GT Advanced facility up to over 2,500 furnaces

Apple should have enough sapphire to cover the displays of both the iWatch and its 4.7- and 5.5-inch iPhones, claims Seeking Alpha's Matt Margolis. Based on supply chain checks, he suggests that GT Advanced's Mesa, Arizona sapphire plant -- which is dedicated to Apple -- will have "ample supply" for all three devices this year. "Additionally, the maximum sapphire screen capacity of the Mesa facility is likely to exceed 200m annual units," he writes.

Margolis observes that GT Advanced has installed over 2,500 furnaces at the Mesa complex, and will work with sapphire boules massed between 200 and 235kg. The company is said to be waiting for one last prepayment from Apple in order to wrap up construction and buy more equipment, but that should happen by the end of June.

The main problems with using sapphire as cover glass are typically thought to be rarity of the mineral and, consequentially, its cost. If Apple can solve that through mass production, it should offer the advantage of displays that are both thinner and tougher than the Corning Gorilla Glass used in current iPhones. That may be especially important in the case of the iWatch, which as a wearable will be exposed to more potential damage.

I have watches with sapphire, plain glass, and mineral crystal, and the sapphire equipped watches have no scratches while the others do. While i am not at all a fan of larger form factor for iPhone, i would be pleased if any i purchase in the future have sapphire screens.